Flushing Meadows, NY -- (Sports Network) - Rafael Nadal's first match as a top seed in a Grand Slam was anything but easy, but the world's top-ranked player did advance in straight sets on the first day of play at the 2008 U.S. Open.

Nadal posted a 7-6 (7-4), 6-3, 7-6 (7-4) victory over German qualifier Bjorn Phau. Another Spaniard, fourth-seeded David Ferrer, also moved on in straight sets, as did sixth-seeded Scot Andy Murray.

Ferrer, a semifinalist last year, shook off a sluggish first set and notched a 7-6 (7-1), 6-2, 6-2 win over Argentina's Martin Vassallo Arguello, while Murray had little trouble in a 6-3, 6-4, 6-0 rout of Sergio Roitman, another Argentine.

Nadal, coming off a gold medal performance at the Summer Olympics, is playing a Grand Slam as a top seed for the first time, having officially usurped Roger Federer as the world's top-ranked player following his victory in Beijing. He earned the top spot thanks to victories over the Swiss superstar in the finals at the French Open and Wimbledon -- the latter ending Federer's reign on the famed grass courts of the All England Club.

Now, Nadal will try to end Federer's grasp of the U.S. Open trophy. Federer, the tournament's second seed, has won the crown at Flushing Meadows four years running.

Nadal, meanwhile, has never been past the quarterfinals of the U.S. Open. He lost to Mikhail Youzhny in the 2006 quarterfinals and last year fell in the fourth round to countrymate Ferrer.

Phau should have been no match for Nadal, who needed nearly three hours to finish him off. Nadal broke Phau's serve just once through the first two sets, then broke for a 5-4 lead in the third only to watch Phau return the favor in the next game. Phau then saved three break points and Nadal held serve to send the set to a tiebreak, which Nadal took control of late.

In all, Nadal converted just 2-of-13 break-point chances and committed 35 unforced errors.

Another Olympian that struggled to get through his opening-round match was James Blake. Blake lost his bronze-medal match in Beijing and seemed sluggish through most of his match with 19-year-old fellow American Donald Young.

The raucous New York crowd got behind the underdog Young when the lefty broke Blake's serve to force a fifth set.

After fending off two break points at 3-3, Young couldn't duplicate the feat in his next service game, and Blake finished off his 6-1, 3-6, 6-1, 4-6, 6-4 thriller to a standing ovation.

Another surprising Day 1 test came in a battle of Argentines, as the up-and- coming Juan Martin del Potro overcame a slow start to top Guillermo Canas. The 17th-seeded del Potro has won the past four tournament he has entered and extended his unbeaten streak to 20 matches in a rather unconvincing 4-6, 7-6 (7-0), 6-4, 6-1 victory.

Other winners on Monday included seventh-seeded David Nalbandian of Argentina, 10th-seeded Stanislas Wawrinka of Switzerland and 16th-seeded Frenchman Gilles Simon.

Nalbandian cruised past Brazil's Marcos Daniel, 6-1, 6-2, 6-4, while Wawrinka advanced with a 7-6 (7-5), 6-3, 6-3 triumph over Italy's Simone Bolelli. Simon needed four sets to dispose of Spain's Marcel Granollers, 6-4, 6-3, 5-7, 6-2.

France's Gael Monfils was also a straight-set winner, as was Germany's Philipp Kohlschreiber. Two minor upsets saw Japan's Kei Nishikori eliminate 29th- seeded Juan Monaco of Argentina in four sets, while Jurgen Melzer came from behind to best No. 27 seed Feliciano Lopez, 4-6, 7-6 (7-5), 6-2, 2-6, 6-4.